Many of the problems associated with the installation and use of floor drain covers are described in my prior U.S. Pat. No. 3,212,416. That structure comprised a unitary plate or disc having a plurality of depending resilient fingers struck therefrom. The fingers cooperated with the drain pipe to frictionally retain the cover in operational position wherein the disc overlaid the surrounding floor surface so that fine finishing of the floor or pipe was not required.
Another of my prior patents is U.S. Pat. No. 4,257,892 which teaches a drain cover having adjustable slugs and camming means for moving the slugs into locking engagement with an associated drain pipe. Those adjustable locking means were thus able to compensate for shape irregularities or minor variations in dimension of the drain pipe.
It is, of course, well known that drain pipes, sewer pipes, and the like, are made in a variety of diameters. The known prior art drain covers, including those shown in my said patents, were capable of installation and operation only in a pipe of a given size. Thus, for example, the prior art drain covers were required to be made and stocked in a number of sizes, such as, 2 inch, 3 inch, or 5 inch, diameter, in order to be usable with drain pipes of those dimensions.
The necessity of making and stocking the drain covers in a number of sizes obviously added to the cost of the device. In addition, considerable inconvenience could be encountered if a particular needed size was in short supply or out of stock. There thus exists a need for a drain cover which is universal and usable with the full spectrum of standard drain pipe sizes.